Metallography is the science and art of preparing a metal surface for analysis by grinding and polishing, and etching to reveal the structure of the specimen. Metallographic and materialographic specimen preparation seeks to find the true structure of the material. Mechanical preparation is the most common method of preparing the specimens for examination.
Mounting of specimens is usually necessary to allow them to be handled easily. It also minimizes the amount of damage likely to be caused to the specimen. Mounting a specimen provides a safe, standardized, and ergonomic way by which to hold a specimen during the grinding and polishing operations. Metallographic specimens are typically mounted using hot mounting or cold mounting. A typical hot mounting cycle will use hot mounting resins and a hot mounting press compressing the mounting media to 4,000 pounds per square inch (28 mega-Pascal) and heat to a temperature of 350° Fahrenheit (180° Celsius). Hot mounting samples take approximately ten minutes to process, but only one mount may be processed at a time. Additionally, hot mounting is not suitable for brittle materials (e.g. ceramics), and edge retention is problematic.
When specimens are very sensitive to pressure or temperature, cold mounts may be made with cold mounting resins. With cold mounting, specimens are placed in a mounting cup and two-part epoxy mounting material is then poured over the specimens. While multiple samples may be made at the same time with cold mounting, it generally take over an hour for the samples to cure.
Improvements in metallographic sample preparation are therefore needed in the art.